Proposed rule - EPA is proposing to correct an error in EPA's regulations for test procedures used in the Corporate Average Fuel Economy (CAFE) program finalized in a 2012 rulemaking. EPA established the procedures under the general provisions of Energy Policy and Conservation Act (EPCA) which authorize EPA to establish test and calculation procedures for CAFE. The correction clarifies the method for how flex-fuel vehicles are accounted for in manufacturer fuel economy calculations in model years 2020 and later. This correction allows the program to be implemented as originally intended in the 2012 rule. This proposed action is not expected to result in any significant changes in regulatory burdens or costs. In the "Rules and Regulations" section of this Federal Register, we are taking direct final action without a prior proposed rule. If we receive no adverse comment, we will not take further action on this proposed rule.